Hollow walled display tray

ABSTRACT

A foldable display tray comprising two pairs of opposed hollow parallel wall panel arrays defining a generally rectangular bottom support panel including means for locking intersecting ends of said wall panel arrays together to prevent collapse thereof and a blank for forming said tray.

United States Patent 7 1 1 Colantoni et al. July 10, 1973 [54] HOLLOW WALLED DISPLAY TRAY 2,447,243 8/1948 Frebl et 3]. 229/34 HW 1 1 Fr-nk 9 m Longmeadow; 21233:??? 3322 E'ZJEEZLZYiTI:31311111132935.1114; 'f Walerhwse, 3,335,936 1 8/1967 Cohen et 229 34 11w wlbraham. both of Mass- 3,539,094 11/1970 O'Connor 229/34 [73] Assignee: Diamond International Corporation,

New York, Primary Examiner-Davis T. Moorhead Att0mey-Karl [211 App]. No.: 257,173

[57] 1 ABSTRACT [2%] Afoldablc display tray comprising o pairs ofopposed d 4 A 34 B hollow parallel wall panel arrays defining a generally 1 e o 31 37 rectangular bottom support panel including means for lockin intersectin ends of said wall panel arrays tog ll th f d bl k f f [56] References Cited gether to prevent co apse ereo an a an or armmg sald tray. UNITED STATES PATENTS 2,345,716 4/1944 Smith 229/34 MW 17 Claims, 22 Drawin Figures HOLLOW WALLED DISPLAY TRAY BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improvement in hollow or tubular trays and more particularly to a tray of the type which is capable of being folded to a flat collapsed condition for storage and/or shipment purposes, and which may be readily set up at the time a package is to be produced; the tray of the present invention is particularly adaptable for the purpose of being set up and forming a frame about an item to be packaged.

2. Description of the Prior Art In the past display trays of the type which the present invention constitutes an improvement have been designed to include means for preventing buckling or collapsing thereof. Some of the means for preventing buckling or collapsing are in the form of frictional locking elements. Other locking elements shown in the prior art have the disadvantage of not being readily accessible for disassembly of the trays after the trays are erected; it then becoming necessary to forcibly collapse the trays with the accompanying tendency of destroying or reducing the effectiveness of the locking elements.

Examples of the prior art trays are represented by the following U.S. Pats. to Smith (No. 2,345,716) and O- Connor (No. 3,539,094) and Davidson (No. 3,227,355).

SUMMARY OF THE INVENTION The present invention comprises a new and improved waste of stock material at a minimum; and to provide a tray which is satisfactory and practical for the purpose intended.

Another object of this invention is to provide a tray equipped with locking elements to prevent undesirable buckling and/or collapsing thereof.

An additional object of this invention is to provide a tray equipped with locking elements which are readily accessible and easily disengaged to permit easy folding of the tray into a-collapsed condition.

It is a further object of this invention to provide a sturdy tray with locking elements equal to the strength of the material thereof.

It is still another object of this invention to eliminate the dependency of a sleeve, shrink film or the like and to prevent the tray from collapsing in normaluse.

With the fulfillment of the above objects the tray accordingto the present invention will not collapse prior to the shrink film covering operation. Additionally the tray according to the present inventionwill be stronger and more stable than would be possible without the novel locking elements. Further a neater tray is provided by virtue of proper alignment of corners firmly fastened. Moreover the locking elements will maintain the tray in erected condition even after removal of the covering sleeve or film.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing, in which there are illustrated two basic complete embodiments of the present invention:

FIG. 1 is a plan view of a blank from which one em- I bodiment of the novel tray is produced;

FIG. 2 is a perspective view of the novel tray, produced with the blank shown in FIG. 1, showing a fragmentary portion of a transparent overwrap of shrink film or the like covering one corner thereof;

FIG. 3 shows a fragmentary portion of the tray of FIG. 2 in perspective as the corner portions are being assembled;

FIG. 4 shows a fragmentary portion of the tray of FIG. 2 with the corner portions of the tray partially assembled;

FIG. 5 shows in perspective the fragmentary corner portions of the tray of FIG. 2 in assembled condition;

FIG. 6 is a fragmentary view in perspective of one end of the tray of FIG. 2 in partially assembled condition looking at the outside of said end;

FIG. 7 is a fragmentary view in perspective of one corner of the tray shown in FIG. 2; in assembled condition;

FIG. 8 is a sectional view in elevation of the tray along the plane 8 8 in FIG. 2; V

FIG. 9 is a sectional view in elevation along the plane 9 9 in FIG. 2; I

FIG. 10 is a fragmentary sectional view in elevation showing an optional arrangement of the lower wallpanels made with the blank of FIG. I;

FIG. 10A is a fragmentary view in perspective of the tray arrangement of FIG. 10, showing in particular details ofcorner portions and lower wall panel;

FIG. 11 is a plan view of a blank for making an alternative embodiment of the novel tray according to this invention;

FIG. 12 is a view in perspective of the assembled tray made with the blank of FIG. 11;

FIGS. l3-17 represent fragmentary portions of the tray made with the blank of FIG. ill and correspond with FIGS. 3-7 of the tray made with the blank shown in FIG. 1;

FIG. 18 is a sectional view in elevation of the tray taken along theplane 18 18 in FIG. 12;

FIG. 19 is a sectional view in elevation of the tray shown in FIG. 12 taken along the plane 19 l9;

' FIG. 20 is a fragmentary view in perspective looking at the bottom of one end of the assembled carton shown in FIG. 12;

FIG. 21 is a fragmentary plan view looking at an optional arrangement of the bottom wall panel elements of the carton made with the blank of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENT which is bordered at opposed pairs of parallel hinge :or

score lines l4, l6 and 18, 20 by tubular wall-panel arrays 22, 24, 26, 28, respectively.

The wall panel element arrays 22 and 24 are mirror images of each other and thus only one of these arrays will be described in detail, the other of which is identified by similar primed reference numerals. The wall panel element array 22 comprises a first or outer side wall panel element 30 having free edges 32 and 34 starting from the respective intersections of fold lines 18 and 20 with fold line 14 and converging in a direction outwardly of the blank 10. The panel element 30 is further defined by a fold line 36 parallel to fold line 14 and terminating at the inner edges of die cut lock tabs 44 and 46. A top wall panel element 38 is hingedly connected to the first or outer wall panel element 30 along fold line 36 and is provided at the opposite ends thereof with primary lock tabs 40 and 42 which are directed outwardly away from the center of the blank and with inwardly directed lock tabs 44 and 46, which are die cut and shall also be referred to as secondary lock tabs. Primary lock tabs 40 and 42 are provided with free edges 48 and 50, respectively, extending generally parallel to fold line 36. Primary lock tabs 40 and 42 are further provided with side edge slits 54 and 56. The function of the slit side edges 54 and 56 will be readily understood from the detailed description herein below.

A second or inner side wall panel element 58 is hingedly connected to the top wall panel element 38 along a fold line 60 and includes free side margins 62 and 64 extending partially alongside the slit side edges 54 and 56, respectively of the tabs 40 and 42. I-Iingedly connected to panel 58 along fold line 66 is a lower wall panel element 68 with side edges 70 and 73 and free margin end edge 71.

wall panel element arrays 26 and 28 are mirror images of each other and thus only one of these arrays will be described in detail, the other of which is identified by similar primed reference numerals. The wall panel element array 26 comprises a first or inner side wall panel element 72 hingedly connected to bottom panel 12 along fold line 18 and defined at the outer edge by a fold line 74 parallel to fold line 18. Formed at opposite ends of the wall panel 72 are end margins 76 and 78 co-linear with fold lines 14 and 16, respectively. Hingedly connected to wall panel element 72 along fold line 74 is a top wall panel element 80 which includes end extension flaps 81 and 83 hinged thereto along fold lines 93 and 95 co-linear with fold lines 14 and 16, respectively. Wall panel element 80 is also formed at opposite ends thereof with outwardly directed die cut notches 97 and 99 extending outwardly beyond fold lines 93 and 95, respectively. Hinged extension flaps 81 and 83 each include a lip 85 and 87 formed over notches 97 and 99, respectively. Extension flaps 81 and 83 are generally triangular in shape with the free edges 85 and 87, respectively, as part of one side thereof. Deviating outwardly from a straight line along the free edges of lips 85 and 87 are protruding ears 89 and 91. These protruding ears 89 and 91, however, are optional and may be omitted on trays of certain sizes. Hingedly connected to the outer edge of panel element 80 along fold line 79 is a second or inner side wall panel element 82. Opposite ends of panel 82 are defined by slits 96, 98 between shoulders 100, 102 and fold line 79, respectively. I-Iingedly connected to panel element 82 along fold line 84 parallel to the previously mentioned fold lines 18, 74, and 79 is a lower panel element 86, which includes a free edge 88. For

convenience, panel elements 82 and 86 include obliquely extending common end edges 104 and 106.

ASSEMBLY AND ERECTION OF THE TRAY Assembly and erection of the blank shown in FIG. 1 into the tray shown in FIG. 2 may be attained with reference to the various fragmentated portions of the tray illustrated in FIGS. 3-7. Initially each of the first panel elements 30, 30' and 72, 72' are folded in an upwardly extending direction along respective fold lines 14, 16 and 18, 20 as outer wall panel elements. Next wall panel elements 38, 38 and 80, are then folded inwardly along the respective fold lines 36, 36' and 74, 74' as top wall panel elements. Then panel elements 58, 58' and 82, 82' are folded downwardly along the respective fold lines 60, 60 and 79, 79' to form inner wall panel elements. To finally position tubular wallpanel element arrays 22, 24 and 26, 28 the wall panel elements 68, 68 and 86, 86 are folded along the respective fold lines 66, 66' and 84, 84' to form lower wall panel elements. As shown in FIGS. 3-7 the fourth wall panel elements 68, 68' and 86, 86' are folded outwardly along the respective fold lines 66, 66' and 84, 84'.

Interlocking arrangement of the corner portions of each of the tubular wall panel element arrays 22, 24 with the arrays 26 and 28 are identical and by way of example the intersecting corner structure of element arrays 26 and 28 are shown in detail in FIGS. 3-5. In this regard it is noted that with top wall panel element folded inwardly along fold line 36 the free edge 50 of primary lock tab 42 is directed inwardly and inserted within element array 28 beneath top wall panel element 80'. It is further noted that slit side edge 56 of primary lock tab 42 is inter-engaged with slit 96 and in frictional retaining relationship therewith. Shoulder 100' is extended into element array 26 beneath top wall panel element 38 and against free side margin 64 of inner wall panel element 58. Notch 97' is pulled down into overlying contact with secondary lock tab 46. Extension flap 81' is then folded downwardly along fold line 93' in the direction of the arrow in FIG. 4 with lip pulled underneath secondary lock tab 46 in positive locking relationship therewith. Flap 81' is then pushed into the opening formed by obliquely extending free edge 34 of outer wall panel element 30 with protruding ear 89 held within element array 26 by outer wall panel element 30 in the manner that extension flaps 83, 83' are pushed into the openings formed between free edges 32', 34 and outer wall panel element 72, 72' as shown in FIGS. 6 and 7. Further, as specifically shown in FIG. 7 protruding ear 91 is pushed into the generally triangular opening at one end of outer wall panel element 30, it is locked within element array 24 since it protrudesibeyond the edge 34'. As both frictional locking elements as well as primary and secondary positive locking elements are provided in each intersection of the wall panel element arrays of the present tray a very rugged and stable tray may be erected in accordance with the present invention. Further because of the accessibility of the positive locking elements, specifically the extension flaps 81, 81' and 83, 83 the tray according to the present invention may be readily disassembled and collapsed from its erected condition.

With reference to FIG. 8 it is noted that protruding ears 89, 89' are more clearly shown to be locked within the intersecting element arrays by edges 32, 34.

With reference to FIG. 9 details of the frictional locking arrangement between the oppositely extending shoulders 100' and 102' of inner wall panel element 82' as they extend behind and against the free side margins of elements 58, 58' are clearly shown therein. Note that the outwardly directed shoulders 100', 102' project beyond adjacent the free marginal ends of and extend for the height of adjacent inner wall panel elements 58, 58'.

As thus described above the tray may then be covered with a shrink film or like element W to enclose the contents therein. Also, as thus described above the tray has been assembledwithout necessity of any adhesive agent, it being clear that the free marginal edges 71, 71 and 88, 88' extend against panel elements 30, 30 and 72, 72, respectively, thereby stabilizing the arrays formed. I

It is noted, however, that in assembling the tray with blank 10, as heretofore described the wall panel elements 68, 68' and 86, 86' may be turned inwardly along their respective fold lines instead of outwardly to provide the optional arrangement illustrated in FIGS. and 10A wherein fourth wall panel elements 68 and 86 are folded inwardly. In this arrangement of the lower wall panel elements an adhesive is applied to the lower surfaces thereof to secure each of these elements to the upper surface of bottom panel 12. It is noted that the tray as assembled may be stored or shipped in the assembled, but folded flat condition.

ALTERNATIVE FORM OF THE INVENTION As an alternative form of the present invention a blank 110 as illustrated in FIG. 11 is provided which may be assembled and erected into the tray shown in FIG. 12. The blank 110 comprises a generally rectangular bottom panel 112 which also is bordered at opposed pairs of parallel hinge or score lines 1 14, 116 and 1 18, 120 by tubular wall-panel element arrays 122, 124 and 126, 128, respectively.

The wall panel element arrays 122 and 124 are also mirror images of each other and thus only one of these arrays will be described in detail, the other of which is identified by similar primed reference numerals. As to element array 122 the basic difference between it and the corresponding element array 22 of the previously described embodiment lies in the fact that first wall panel element 130 and third wall panel element 158 are provided with the general shapes of third wall panel element 58 and first wall panel element 30 of the preferred embodiment. An additional difference in element array 122 lies in the fact that primary lock tabs 140, 142 and secondary die cut lock tabs 144 and 146 are directed in opposite directions from corresponding elements in the second wall panel element 38 of the blank 10 of FIG. I. It will subsequently be clear that in assembling the blank 110 to form the tray, some of the wall panel elements 130, 138, 158 and 168 of necessity must be folded in a direction opposite to that in which corresponding wall panel elements 30, 38, 58 and 68 of the blank 10 are folded.

The wall panel element array 122 comprises four basic wall panel elements 130, 138, 158 and 168 successively hingedly connected to bottom panel 112 and to each other, respectively, along parallel fold lines 114, 136, 160, and 166. The first wall panel element 130 comprises free edges 132, 134. The second wall panel element 138 comprises inwardly directed primary lock tabs 140 and 142 at opposite ends thereof and outwardly directed die cut secondary lock tabs 144, 146. Lock tabs 144 and 146 are outwardly directed beyond fold line 160. Primary lock tabs 140, 142 comprise free edges 148, 150 and slit side edges 154, 156, respectively. Third wall panel element 158 comprises free side margins 162, 164 diverging from secondary lock tabs 144, 146, respectively. Fourth wall panel element 168 comprises side edges 170, 173 and free edge 171 and also a glue section 268.

Wall panel element arrays 126 and 128 are mirror images of each other and thus only one of these arrays will be described in detail, the other which is identified by similar primed reference numerals. The wall panel element array 126 comprises wall panel elements 172, 180, 182, and 186 successively hingedly connected to bottom panel 112 and to each other respectively along parallel hinge fold lines 118, 174, 179, and 184. Element array 126 differs from corresponding element array 26 of the blank 10 shown in FIG. 1 in that the shoulders 200, 202 are provided on first wall panel element 172 instead of on the third wall panel element 82 with shoulders 100, 102 as shown in FIG. 1. Additionally, the extension flaps at 181, 183 at opposite ends of the second wall panel element as shown in FIG. 11 are provided with lips 185, 187 directed inwardly and over die cut notches 197, 199, respectively instead of being directed outwardly over corresponding notches as provided on the second wall panel element of the blank in FIG. 1. Again, because of the difference in the wall panel elements 172, 180, 182 and 186 one or more of these elements will of necessity be folded in a direction different from that of corresponding elements of the blank 10 to assemble a tray.

Turning now to FIGS. 1316 with particular reference to FIG. 13 it is noted that in assembling a tray with the blank 110 the respective wall panel elements 130, 138, 158, and 168 of element array 122 and the respective wall panel 172, 180', I82, and 186' of element array 128 are both formed by folding the first wall panel elements so as to extend upwardly as inner wall panel elements, the second wall panelelements outwardly as top wall panel elements, the third wall panel elements downwardly as outer wall panel elements and the fourth wall panel elements inwardly as lower wall panel elements, respectively, and whereupon glue sections 268 and 286 are adhesively applied to the undersurface of bottom panel 112 and also one to the other in assembling the tray.

Further in assembling the tray primary lock tab 142 is inserted within element array 128 beneath top panel element 180' with slit side edge 156 interengaging with slit 196' in frictional relationship therewith. In the erected condition shoulder 200' will also be in frictional engagement with free edge 134. Extension flap 181 may then be applied downwardly in the direction of the arrow shown in FIG. 14 with notch 197' in overlying relationship with die cut secondary lock tab-146 and lip pulled around and beneath lock tab 146 much in the manner that the lock tab 187 is applied in FIG. 17. Protruding ear 189' will then be pushed past the obliquely extending edge of outer panel 158 of .element array 122 into locking relationship therewith.

It will be clear that as the first wall panel element 130 is folded along fold line 114 in an upwardly extending direction and the second wall panel element 138 is folded outwardly along fold line 136, these panels will become inner and top wall panel elements, respectively, and that primary lock tabs 140, 142 will be directed inwardly. It will be further clear that as the third wall panel element 158 is folded along fold line 160 in a downwardly direction and the fourth wall panel element 168 is folded inwardly along the fold line 166, these panels will become outer wall panel elements and lower wall panel elements, respectively, and that the n free side margins 162 and 164 will each define one side of a generally triangular end opening. Similarly wall panel elements 172, 180, 182, and 186 of wall panel element array 126 will respectively become inner wall panel element, top wall panel element, outer wall panel element, and lower wall panel element as they are folded along fold lines 118, 174, 179, and 184.

The final step in erecting the tray with blank 110 would be in applying the various extension flaps 183, 183', etc. downwardly in the direction of the arrows shown in FIG. 16 and passing the protruding ears 191, 191' past the edges 162', 164' into the element arrays 126, 128 in locking relationship therein.

FIGS. 18, 19 and 20 relate to an arrangement wherein the end lower panel element 168 is lapped directly against the undersurface of the bottom panel 1 12 and the side lower panels 186, 186 are lapped against the undersurface of both the lower panel 168 and the undersurface of the bottom panel 112. The glue portions 286 and 286" as shown in FIG. 18 are applied to the undersurface of lower panel 168. FIG. 19 shows the edge 188' of glue section 286 snugly against the undersurfaces of lower panels 168, 168 and bottom panel 112. It is noted that in this particular arrangement the width of glue portions 268 and 268, as shown in FIGS. 11 and 20 is substantially equal to that of bottom panel 112 with which these glue portions are in full contact. Also, glue portions 286 and 286' extend for the full length of the tray that is formed.

FIG. 21 shows an optional arrangement of the lower panel elements wherein the lower panel elements 186, 186' are initially applied to the undersurface of the bottom panel element 112 and the lower panel element 168 applied thereafter to the undersurfaces of the lower panel elements 186, 186' and the bottom panel element 112. For forming a tray with this optional arrangement of lower panel elements the blank in FIG.

11 is modified to the extent that end glue portions 268 and 268' extend for the full width of the tray and side glue portions 286 and 286' are reduced in length to that of bottom panel 112 with which they are in full contact.

It is to be clearly understood that while two basic embodiments of the present invention have been illustrated and described herein, numerous variations or modifications therein may occur to those having skill in this art and what is intended to be covered herein is not only the illustrated forms of the invention, but also any and all modified forms thereof as may come within the spirit of said invention.

What is claimed is:

l. A hollow-walled display tray comprising a rectangular bottom panel bordered by opposed pairs of parallel wall panel element arrays respectively connected at opposed pairs of parallel hinge lines extending along said bottom panel; each wall panel element array starting from one of said hinge lines and comprising a first side wall panel element extending upwardly therefrom, a top wall panel element, a second side wall panel element and a lower wall panel element; one of said first and second side panel elements of each of one pair of opposed wall panel element arrays constituting an inner wall panel element and including at terminal portions thereof outwardly directed shoulders projecting beyond adjacent free marginal ends of and extending the height of adjacent inner wall panel elements of said other pair of opposed wall panel element arrays; the top wall panel elements of the other pair of opposed wall panel arrays including inwardly directed lock tabs extending beneath adjacent top wall panel elements of said one pair of opposed wall panel element arrays; said top wall panel elements of the other pair of opposed wall panel element arrays also including outwardly directed lock tabs formed thereon; each top wall panel element of said one pair of opposed wall panel element arrays also including an outwardly directed notch and a hinge flap at opposite ends thereof with each notch overlying an adjacent outwardly directed tab and the corresponding hinge flap extending downwardly with a lip extending beneath the adjacent notch and outwardly directed tab in locked relationship therewith.

2. The display tray as recited in claim 1 wherein one of said first and second wall panel elements of each of the other pair of opposed wall panel element arrays constitute an outer wall panel element with free edges converging in an upward direction to form spacedapart openings with adjacent outer wall panel elements of said one pair of panel arrays, each of said hinged flaps being forceably insertable into one of said openmgs.

3. The display tray as recited in claim 2 wherein each of said inner wall panel elements of said one pair of opposed wall panel element arrays and the corresponding top wall panel element are formed with a slit along upper edges of said outwardly directed shoulders whereby top wall panel elements of said other pair of opposed wall panel element arrays are frictionally held together thereby.

4. The display as recited in claim 3 wherein said first and second side wall panel elements of each of said parallel wall 'panel element arrays constitute outer and inner wall panel elements, respectively.

5. The display tray as recited in claim 4 wherein each of said lower wall panel elements is hinged to and extends outwardly from an inner wall panel element with its free edge abutting against the inside surface of an outer wall panel to stabilize the wall panel element array formed thereby.

6. The display tray as recited in claim 4 wherein each of said lower wall panel elements is hinged to and extends inwardly from an outer wall panel element and is secured to said bottom panel.

7. The display tray as recited in claim 6 whereby each of said lower wall panel elements is adhesively secured to said bottom panel.

8. The display tray as recited in claim 3 wherein said first and second side wall panel elements of each of said parallel wall panel elements constitute inner and outer wall panel elements, respectively.

9. The display tray as recited in claim 8 wherein the lower wall panel elements of said other pair of opposed wall panel element arrays are secured to said bottom panel and the lower wall panel element of said one pair of opposed wall panel element arrays are secured to said bottom panel and said lower wall panel element of said other pair of opposed wall panel element arrays.

10. A blank for producing a hollow-walled display tray comprising a rectangular bottom panel including marginal fold lines extending about the periphery thereof two pairs of opposed arrays of wall panel elements connected to opposed parallel margins of said bottom panel, each of said arrays including an inner wall panel, a top wall panel, an outer wall panel and a bottom wall panel connected on mutually parallel fold lines, one of said inner and outer wall panels of each of one of said two pairs of opposed arrays including at terminal portions thereof outwardly directed shoulders; said top wall panels of said one of said two pairs of opposed arrays each including a hinged flap extension with a lip formed around a notch; each of said top wall panels of the other of said two pairs of opposed arrays including at opposite sides thereof oppositely directed lock tab portions for cooperation with said outwardly directed shoulders and said hinged flap extensions to retain a tray assembled from said blank in erected condition.

11. The blank as recited in claim 10 wherein the outer wall panel of said other of said two pairs of op posed arrays are formed with side edges extending obliquely with respect to the longitudinal axis of said blank and said hinged flap extensions being each adapted to be inserted in an opening defined by one of said obliquely extending side edgesand locked in position thereby.

12. The blank as recited in'claim 11 wherein said lock tab portions are directed both outwardly and inwardly in the preassembled condition of said blank and said obliquely extending side edges are formed on an outer wall panel and converge in a direction outwardly of said blank.

13. The blank as recited in claim 10 wherein lock tab portions are directed both inwardly and outwardly, respectively, in the preassembled condition of said blank and said obliquely extending side edges are formed on said outer wall panel and diverge in a direction outwardly of said blank.

14. The blank as recited in claim 11 wherein each of said hinged flap extensions includes a protruding ear portion adapted to be forceably pushed past the edge of an opening defined by one of said obliquely extending side edges in the assembled tray.

15. The blank as recited in claim 14 wherein said bottom wall panels of one of said pairs of arrays is substantially equal in width to that of said bottom panel.

16. The blank as recited in claim 14 wherein said bottom wall panels of one of said pairs of arrays is substantially equal in length to that of said bottom panel.

17. The display tray as recited in claim 2 wherein each of said hinged flaps includes a protruding ear extending beyond the free edge of the adjacent opening whereby the respective hinged flap thereof upon being inserted into an adjacent opening is lockingly retained therein.

t i i 

1. A hollow-walled display tray comprising a rectangular bottom panel bordered by opposed pairs of parallel wall panel element arrays respectively connected at opposed pairs of parallel hinge lines extending along said bottom panel; each wall panel element array starting from one of said hinge lines and comprising a first side wall panel element extending upwardly therefrom, a top wall panel element, a second side wall panel element and a lower wall panel element; one of said first and second side panel elements of each of one pair of opposed wall panel element arrays constituting an inner wall panel element and including at terminal portions thereof outwardly directed shoulders projecting beyond adjacent free marginal ends of and extending the height of adjacent inner wall panel elements of said other pair of opposed wall panel element arrays; the top wall panel elements of the other pair of opposed wall panel arrays including inwardly directed lock tabs extending beneath adjacent top wall panel elements of said one pair of opposed wall panel element arrays; said top wall panel elements of the other pair of opposed wall panel element arrays also including outwardly directed lock tabs formed thereon; each top wall panel element of said one pair of opposed wall panel element arrays also including an outwardly directed notch and a hinge flap at opposite ends thereof with each notch overlying an adjacent outwardly directed tab and the corresponding hinge flap extending downwardly with a lip extending beneath the adjacent notch and outwardly directed tab in locked relationship therewith.
 2. The display tray as recited in claim 1 wherein one of said first and second wall panel elements of each of the other pair of opposed wall panel element arrays constitute an outer wall panel element with free edges converging in an upward direction to form spaced-apart openings with adjacent outer wall panel elements of said one pair of panel arrays, each of said hinged flaps being forceably insertable into one of said openings.
 3. The display tray as recited in claim 2 wherein each of said inner wall panel elements of said one pair of opposed wall panel element arrays and the corresponding top wall panel element are formed with a slit along upper edges of said outwardly directed shoulders whereby top wall panel elements of said other pair of opposed wall panel element arrays are frictionally held together thereby.
 4. The display as recited in claim 3 wherein said first and second side wall panel elements of each of said parallel wall panel element arrays constitute outer and inner wall panel elements, respectively.
 5. The display tray as recited in claim 4 wherein each of said lower wall panel elements is hinged to and extends outwardly from an inner wall panel element with its free edge abutting against the inside surface of an outer wall panel to stabilize the wall panel element array formed thereby.
 6. The display tray as recited in claim 4 wherein each of said lower wall panel elements is hinged to and extends inwardly from an outer wall panel element and is secured to said bottom panel.
 7. The display tray as recited in claim 6 whereby each of said lower wall panel elements is adhesively secured to said bottom panel.
 8. The display tray as recited in claim 3 wherein said first and second side wall panel elements of each of said parallel wall panel elements constitute inner and outer wall panel elements, respectively.
 9. The display tray as recited in Claim 8 wherein the lower wall panel elements of said other pair of opposed wall panel element arrays are secured to said bottom panel and the lower wall panel element of said one pair of opposed wall panel element arrays are secured to said bottom panel and said lower wall panel element of said other pair of opposed wall panel element arrays.
 10. A blank for producing a hollow-walled display tray comprising a rectangular bottom panel including marginal fold lines extending about the periphery thereof two pairs of opposed arrays of wall panel elements connected to opposed parallel margins of said bottom panel, each of said arrays including an inner wall panel, a top wall panel, an outer wall panel and a bottom wall panel connected on mutually parallel fold lines, one of said inner and outer wall panels of each of one of said two pairs of opposed arrays including at terminal portions thereof outwardly directed shoulders; said top wall panels of said one of said two pairs of opposed arrays each including a hinged flap extension with a lip formed around a notch; each of said top wall panels of the other of said two pairs of opposed arrays including at opposite sides thereof oppositely directed lock tab portions for cooperation with said outwardly directed shoulders and said hinged flap extensions to retain a tray assembled from said blank in erected condition.
 11. The blank as recited in claim 10 wherein the outer wall panel of said other of said two pairs of opposed arrays are formed with side edges extending obliquely with respect to the longitudinal axis of said blank and said hinged flap extensions being each adapted to be inserted in an opening defined by one of said obliquely extending side edges and locked in position thereby.
 12. The blank as recited in claim 11 wherein said lock tab portions are directed both outwardly and inwardly in the preassembled condition of said blank and said obliquely extending side edges are formed on an outer wall panel and converge in a direction outwardly of said blank.
 13. The blank as recited in claim 10 wherein lock tab portions are directed both inwardly and outwardly, respectively, in the preassembled condition of said blank and said obliquely extending side edges are formed on said outer wall panel and diverge in a direction outwardly of said blank.
 14. The blank as recited in claim 11 wherein each of said hinged flap extensions includes a protruding ear portion adapted to be forceably pushed past the edge of an opening defined by one of said obliquely extending side edges in the assembled tray.
 15. The blank as recited in claim 14 wherein said bottom wall panels of one of said pairs of arrays is substantially equal in width to that of said bottom panel.
 16. The blank as recited in claim 14 wherein said bottom wall panels of one of said pairs of arrays is substantially equal in length to that of said bottom panel.
 17. The display tray as recited in claim 2 wherein each of said hinged flaps includes a protruding ear extending beyond the free edge of the adjacent opening whereby the respective hinged flap thereof upon being inserted into an adjacent opening is lockingly retained therein. 